Light signal for railroads



April 22, 1947. JU 2,419,265

LIGHT SIGNAL FOR RAILROADS Filed Jan. 7; 1944 5??? l 1 l l l i I i l 59 I l I I I 49 I I l i i I I i 48 Patented Apr. 22, 1947 UNITED STATES PATENT OFFICE LIGHT SIGNAL FOR RAILROADS Thomas J. Judge, Rochester, N. Y., assignor to General Railway Signal Company, Rochester,

10 Claims. 1

This invention relates in general to light signals of the searchlight type, as used particularly in railway operation, and has more special reference to improvements in light signals.

The light signal of the present invention is to be considered in the nature of an improvement over the prior application of O. S. Field, Ser. No. 361,060, filed October 14, 1940, now Patent #2376534, dated May 22, 1945; and no claim is made herein to any subject matter common with such prior application, Since the specific con struction of a light signal of the type employed in the embodiment of the present invention has been shown in detail in the above mentioned prior application, it will only be disclosed in this application in a diagrammatic manner to that extent necessary for a complete understanding of the pplicants invention.

In railway practice, in many situations, transient conditions extending over only a short time often occur and if not provided against may cause improper and undesired operation of various devices as for example light signals.

Among the objects of the present invention is to provide an improved type of searchlight signal involving primarily new and improved circuit arrangements for the operating devices of the signal for preventing undesired and improper operation during various transient conditions.

Further objects, purposes and characteristic features of this invention will appear as the description progresses, reference being made to the accompanying drawing showing, solely by way of example, and in a wholly diagrammatic manner, and in no way whatsoever in a limiting sense, two forms which the invention can assume. In the drawing:

Fig. 1 is a wholly schematic showing of one form which the invention can assume.

Fig. 2 is a wholly schematic showing of a second form which the invention can assume.

With reference to the drawing, and first to Fig, 1, there is here shown a portion of an improved signal including one form of applicants invention. This signal, as disclosed in the prior Field application above referred to, has a spectacle I carrying colored roundels R, Y, and G which are respectively red, yellow and green in color. It is biased, as shown, to position the red roundel opposite the light source represented in the drawing as a filament.

The spectacle is mounted on an arm i2, which is carried on a pivoted shaft l3, which shaft car-- ries a crank I3 connected to the depending arm '14 of a T-shaped floating lever having side arms l5 and I6. Arms l5 and I6 are connected, respectively, to armatures l1 and ll! of operating members YG and RY.

The operating members each include not only an armature but a core pole shoe and an energizing winding. The operating member RY includes a core I9, having a pole shoe 20 and an operating winding 2|, together with a short circuited low resistance coil or slug 22 on the core. This member 22, together with proper adjustment of the air gap and the level of energization of the winding, results in making this operating member slower to act than the other operating member, and to have a pick-up time which is long relative to its release time. The operating member YG, has a pole shoe 23 and a core 24 on which is an energizing winding constituted by an upper winding portion 25 and a lower winding portion 26.

These operating windings are connected together through a full-wave rectifier 21 so that current must pass through winding 2|, always in the same direction, regardless of the polarity of current applied to energizing the lead-in Wire 28. The direction of flow of current, however, in the two half windings 25 and 2B of the YG operating member is controlled by the polarity of current applied thereto, and this member is polarized by a permanent magnet 29 whereby were it not for the circuit arrangement to be described below and constituting part of the present invention, operating member YG would be effectively energized to pick up its armature on only momentarily receiving energy of plus or normal polarity but not operate upon receiving energy of negative or reverse polarity.

The arms I5 and [6 are pivotally connected respectively to armatures l7 and 18 by sliding universal joints, comprising, the two balls Il and E8 in place in the armature and each receiving a forked end I1 and I8 on the ends of the respective arms 15 and [6. This construction is identical with that disclosed in the application filed of even date herewith in the name of O. S. Field, and hence should require no more detailed description in this disclosure.

The lower half winding 26 of the operating member YC- is connected as shown by wires 29 and 30 to contact points of the RY operating member, whereby when the armature l8 of operating member RY is in released position (as shown in the drawings), this lower half winding 26 is pole changed with respect to the upper half winding 25 so as to cause the half windings to oppose each other, the control circuit including 3 the contact fingers S2 and 33. When, however, contacts 32 and assume their attracted position and so make up their front points, the lower half winding 26 is connected in circuit in the direction to aid the upper half winding The energy for operating signal Sb passes through wire 23, the upper half winding '25 from top to bottom and in a counterclockwise direction as viewed from the top, wire rectifier 22', winding 2! from top to bottom, the rectifier wire 35, contact 32 and back point wire '28, the lower half winding 2L- in a clockwise direction as viewed from above.

If, however, contact finger is in its attracted position, the circuit then includes wire 39, the lower half winding '2 in a counter-clockwise direction, etc, Accordingly, due to this pole changing of the two halves of the winding of the Y operating member, armature ll of this member remains in its released position regardless of the polarity of energization of its winding, until after armature !8 of operating member RY has picked up and so has made up contact fingers 32 and 33 and their front points.

The purpose of the above described circuit arrangement is to prevent a faulty operation of the signal under transient conditions which may ocour in practice. In order to explain one of these conditions and the possibility of improper operation due to it, the signal Sb is shown in connection with a stretch of single track separated into isolated track sections by insulating joints ll, one complete section B being shown, with the adjacent ends of sections A and C. The sections are each supplied with a usual source of energy, limiting resistance, and track relay, as, in the case of section B, the battery 42, the limiting resistance 43, and the track relay 4:! with contact finger 45.

Shown as occupying section B is a vehicle 45, which is assumed to be travelling at a fast rate and to be short and light. Thus, when it passes out of section B and into section C, there is a short period or" time when track relay 44 has picked up its armature but track relay 4'! of block C has not yet released, or if it has released, the red-yellow operating member of the signal So has not released, and hence its contact finger $8 is still in its attracted position and energy of nor mal or positive polarity is applied to the line wire 49 to thereby momentarily energize signal Sb with energy of normal polarity. Were it not for the special circuit arrangement constituting part of the present invention, as described above, upon receiving energy of positive or normal polarity, spectacle l would be moved to the right to display a yellow indication which indication would shortly thereafter change to a red. and then back to a yellow indication because of the making up of contact finger 48 with its back point, thus to reverse the polarity of energy applied to signal Sb. This would result in what can be termed a flash of the yellow and thus cause a signal operation which is confusing, and undesirable, and possibly dangerous. This is assuming that the operating member RY is sufficiently slow acting due to the copper slug 2 as to not respond to the above described transient energization oi the normal polarity. Er it were not for this retarded response of the operating member RY, then such transient normal energization of the signal might result in the display of a false green indication. However, with the signal organized as presently to be described in detail, such a ransient normal energization does not cause any undesirable indication of the signal.

With the arrangement of circuits as described above, however, the positive polarity of energizetion does not persist long enough to allow the slow pick up operating member RY to pick up its armature and cause its contact fingers 32 and 33 to make up their front point. While these contact fingers 32 and 33 are making up their back points, the two halves 25 and 28 of the winding of operating member YG of signal Sb oppose or buck out each other, so that armature i! cannot pick up.

Thus, the signal, as Sb, does not respond to the plus or normal energization during the short time that, in this situation, it exists, and thus any flash of the yellow or green is prevented, Of course, after a relatively short period of time, the pola 'ity of energy applied to wire t9 changes to reverse or negative, which polarity of energy cannot cause the picking up of armature ll of the polarized operating member YG, but can pick up armature E8 of operating member RY. This is as it should be, since it obvious with this construction of spectacle operating members, when either 0 era-ting member picks up its armature, it pr duces a yellow indication and when both armatures are picked up at the same time, a green indication is produced. Thus, the signal of the present invention does not improperly respond to transient normal energization under trafiic conditions above described, and when it does respond after a time suiiicient to mask out the undesired transi nt energization, it responds properly to the reverse polarity of energization which is then properly applied in accordance with trail-lo conditions, and displays a yellow indication as it should for the entrance to a block immediately to the rear of an occupied block.

Referring now to Fig. there is here shown a modified form of the invention which is shown in connetcion with a train control system of the intermittent inductive type in general, such, for example, as disclosed in detail in the patents to Bushnell, No. 1,? 7,330, granted June 11, 1929, and No. 1,689,228, granted October 30, 1928. Only so much of the train control system as is absolutely essential for an understanding of this invention, is shown and described in the present specification.

In Fig, 2 is showna stretch of single track separated into isolated track sections by insulating joints 60, one complete section E, being shown together with the adjacent ends of the sections D and F. Each section includes a usual source of energy as, in connection with section E, the battery 61, an adjustable resistance 62 and a track relay E3. Each section has associated with it a light signal of the SC type, the signal Se being associated with section E and the signal Sf being associated with the section F. Shown as occupying the section E is a vehicle 64 which is assumed to be a short fast travelling light vehicle. Shown as occupying section D is a vehicle 65 which is equipped with car-carried receiver 66 positioned to at times inductively cooperate with a wayside inductor 61 in the wayside and at the entrance end to block E.

The signal employed in connection with this form of the invention, as for example, signal Se is very similar in most respects to signal Sb described above. It has a spectacle E8 operable through a floating lever 69 and crank 10 to assume various positions to display various aspects. As described above, the armatures H and 12 of the operating members RY and YG- respectively are pivotally connected to lever 69. The RY operating member has a control winding 13 which is now polarized and is connected to a full-wave rectifier 14 whereby it is always energized in the same direction, regardless of the polarity of energy applied to the signal and does not release on reversal of polarity of signal energizing current. This operating member RY is made slow acting as by a slug [5, etc. as described above and as above has a pick-up time that is longer than its release time.

The winding of the YG operating member is separated into two halves, as in signal Sb described above, it having an upper half 16, and a lower half TI, and being polarized by a permanent magnet 18. The lower half winding 11, at about its mid point, is tapped by a wire 19, connected to a back point of contact finger 80, of the RY operating member. The contact finger 8B of the operating member RY makes up this back point when as shown in the drawing, winding 13 is deenergized. Under these conditions, the lower portion of the lower half winding 11 of operating member YG is shunted out of the signal energizing circuit and hence regardless of energization of the signal through wire 3i, so long as the operating member RY has its armature in retracted position, armature l2 of operating member YG cannot move to its attracted position.

The shunting out of the lower part or" the lower half winding H can be readily understood by considering the signal energizing circuit. This circuit includes the upper half windin rectifier M, winding 13, rectifier 14, wire 82 and the upper part of the lower half winding ll. If con tact 80 be retracted, however, (as shown in the drawings) the circuit includes wire '59, back point of contact 80, and wire 84 to common C. If, however, contact finger 80 is in attracted position the lower portion of lower half winding fl is included in the energizing circuit, which includes the lower portion of TI to common. Thus this portion is energized with normal or positive polarity and the polarized operating member YG picks up its armature 12.

It should be noted that in the customary manner, the wayside inductor 61 for block E has its winding connected to wires 35 and S6 and the winding is closed by contact finger 81 of armature 12 when armature I2 is in its attracted position. In other words, the wayside inductor is choked so as to be ineffective to require acknowledgement or other act by the engineer upon his train passing over the inductor, in order to avoid a penalty. As is usual in such train control sys tems, and as clearly disclosed in the patents above referred to, if an unchoked inductor is passed without acknowledgment or other required act, a penalty is incurred, and, it should be noted, the wayside inductor is unchoked under caution and danger conditions and is choked only under proceed or clear conditions.

We can now assume that vehicle 64 passes out of section E and enters section F, and, as in the above description of Fig. 1, a temporary energization of signal Se by energy of normal or positive polarity occurs, at which time, of course, track relay 63 has picked up its contact finger 63 to make up its front point.

Since the RY operating member is so slow acting as not to respond to this temporary condition, and since the circuit arrangement as described just above, is such that the YG operating member cannot respond until after the associated RY member has responded, there is no response by the signal to this momentary positive energization of the signal. Accordingly, vehicle 65 approaching a red signal should acknowledge and if there is no acknowledgment, a penalty is incurred, since the wayside inductor 61 is unchoked due to contact finger 81 being in retracted position.

If, however, this novel circuit arrangement for shunting out a portion of the winding of the YG member, so long as the RY member is in released position, were not employed an improper operation would occur. Upon being energized with energy of normal or positive polarity, the YG operating member would pick up its armature, while the slower acting RY operating member would not have picked up its armature. This would result in the signal displaying a yellow indication, which would indicate to the engineer of the approaching vehicle 65 that he should acknowledge. However, under these conditions the wayside inductor is choked and ii the engineer fails to acknowledge either purposely or by neglect, he nevertheless receives no penalty, and thus is inclined to disregard the warning signals and become negligent in the operation of his vehicle. Thus, in some other situation, where real danger exists, he may likewise fail to acknowledge and so cause a serious accident. Again, if the RY member were not slower acting than the YG member, in like circumstances, both members would pick up to display a green signal to vehicle 85, to indicate to the engineer that he need not acknowledge, whereas in actuality an acknowledging condition, caution, does exist.

By means of the circuit arrangement described above in connection with Fig. 2, this improved type signal can be used in connection with intermittent inductive train control systems, with the assurance that the engineer must comply with the requirements of the signal as regards acknowledgment or else be subjected to the penalty.

The above rather specific description of two forms of this invention i given solely by way of example, and is not intended, in any manner whatsoever, in a limiting sense. It is to be understood that various modifications, adaptations and alterations may be applied from time to time to meet the requirement of expediency and practice, without, in any manner, departing from the spirit and scope of the invention, except insofar as it may be limited by the appended claims.

Having described my invention, I now claim:

1. In a light signal of the Searchlight type, a movable spectacle operable to different positions to select the indications to be displayed by the signal, two electromagnets each having a cooperating armature normally biased to one position but actuated to an attracted position when that electromagnet is energized, one of said electromagnets being polarized and the other nonpolarized, means operatively controlled by said armatures to operate said spectacle from its normal position to a second position when said armature of said non-polarized electromagnet is in an attracted position and to a third position when both of said armatures are in attracted positions, energizing circuit means for connecting said electromagnets in series, said circuit means including a rectifier for always energizing said non-polarized electromagnet in the same direction regardless of the polarity applied to the energizing circuit means, and means including contacts operated by said armature of said nonpolarized electromagnet for rendering the energization of said polarized electromagnet inefiective to move its armature to an attracted position until said armature of said non-polarized electromagnet has assumed its attracted position.

2. In a light signal of the searchlight type, a spectacle operable to different positions to select the indications to be displayed by said signal, two electromagnets each including an armature and an energizable winding for moving its armature from a retracted position to an attracted position, one of aid electromagnets being polarized and the other being non-polarized, and said winding of said polarized electromagnet being divided into two parts, means operatively controlled by said armatures to operate said spectacle from a normal biased position to a second position when said armature or said nonpolarized electromagnet is in an attracted position and to a third position when both said armatures are in attracted positions, contacts operated by said armature of said non-polarized electromagnet, and an energizing circuit for connecting said windings of said electromagnets in series and including said contacts for connecting one part of the winding for said polarized magnet in said circuit to produce magnetism in opposition to the other pa 't while said non-polarized electromagnet has its armature in a retracted position but acting when such armature is in an attracted position to connect such :9 part of the winding of said polarized electromagnet as to produce magnetism additive with the magnetism produced by the other part, whereby the armature of said polarized electromagnet is actuated to an attracted position in response to the energization of said circuit means with only a particular polarity with such response subsequent to the response of the armature of said nonpolarized electromagnet to current flow in said energizing circuit.

3. In a light signal of the searchlight type, a movable spectacle operable to different positions from a normal position to select the indications to be displayed by the signal, two electromagnets each having a cooperating armature'and an energizable winding for causing the actuation of the associated armature from a normal biased position to an attracted position, one of said electromagnet bein polarized and the other nonpolarized, and said winding of said polarized electromagnet comprising two parts, means operatively connecting said armatures to said spectacle for operating said spectacle from its normal position to a second position when said armature of said non-polarized electromagnet is in an attracted position and to a third position when both said armatures are in attracted positions, contacts operated by said armature of said nonpolarized electromagnet, and energizing circuit means for connecting said windings of said electromagnets in series and including said contacts for shunting one of said two parts of the winding for said polarized electromagnet while'said armature of said non-polarized electromagnet is in its biased position, whereby the armature of said polarized electromagnet is actuated to an attracted position only in response to a particular polarity of energization of its windings and then subsequent to the response of the armature of said non-polarized electromagnet to current flow in said energizing circuit.

4. In a light signal of the searchlight type, a

movable spectacle operable to different positions to select the indications to be displayed by the signal, electromagnetic means for governing the operation of said spectacle to its different positions and including a polarized electromagnet and a non-polarized electromagnet, contacts operated by said non-polarized electromagnet, a short circuited winding associated with said nonpolarized electrcmagnet to retard the response of said spectacle and said contacts to the energize.- tion and deenergization of that electromagnet, circuit means for connecting said electromagnets in series and including rectifying means to supply said non-poiarized electromagnet with current flow in the same direction regardless of the polarity of current applied to said energizing circuit means, circuit means also being governed by said contacts to render said polarized electromagnet responsive to the energization of said circuit means only after the response of said non-po1ari"ed electromagnet, whereby the quick reversal in polarity of energization of said circuit means does not cause said non-polarized electroniagnet to shift its control of said spectacle 5 and contacts, and whereby the polarized electromagnet rendered slower in response than said non-polarized electromagnet to the energization of said circuit means.

5. In a color light signal of the search light type, a spectacle movable to different positions to select the indications to be displayed by the signal, a neutral electro-magnet and a polarized electro-magnet each having a cooperating armature biased to the retracted position for moving said spectacle to a particular position to give clear indication when the armatures of both of said electro-magncts are in their attracted positions, circuit means for energizing said polarized electromagnet with current of one polarity or the other and applying current in one direction in each case to said neutral electromagnet, means for rendering said neutral electromagnet slow acting in attracting its armature, and means including contacts operated by the armature of said neutral electro-magnet for renderin polarized electro-magnet ineffective to attract its armature when energized until after the armature of said neutral electro-magnet has been operated, whereby temporary energization of said electro-magnets by said circuit means with the polarity tending to operate both armature-s is not effective to move said spectacle to said particular clear indication position.

l agnetic operators, each including an armature an energizing coil for moving its armature from a retracted to an attracted position, means atively connecting the armatures to said spe acle so that the spectacle assumes its second I on when the armature associated with one i an attracted position and its third posiwhen both armature-s are in attracted ,n energizin circuit for the two coils, nto. t means in said circuit making the CL-il i l more its armature to an tion by means of pole changing one other coil with respect to the rest i coil until after said one coil has its armature to attracted position. In a light signal of the searchlight type, a spectacle biased to one position and movable to a second and a third position to determine the indications to be displayed by the signal, two electromagnetic operators each including an armature and an energizing coil for moving its armature from a retracted to an attracted position, means operatively connecting the armatures to said spectacle so that the spectacle assumes its second position when the armature associated with one coil is in an attracted position and its third position only when both armatures are in attracted positions, an energizing circuit for the two coils, and contact means in the circuit making the other coil ineiiective to move its armature to an attracted position by shunting a portion of said other coil out of the circuit until after the armature associated with said one coil has assumed its attracted position.

8. In a light signal of the searchlight type, a movable spectacle biased to one position and movable to a second and a third position to determine the indications to be displayed by the signal, two electromagnetic operators each including an armature and an energizing coil for moving its armature from a retracted to an attracted position, means operatively connecting the armatures to the movable spectacle so that the movable spectacle assumes its second position when the armature associated with one coil is in an attracted position and its third position only when both armatures are in attracted positions, an energizing circuit for the two coils, means in the circuit makin the other coil ineiiective to move its armature to an attracted position until after the armature associated with said one coil has assumed its attracted position, and means associated with said one coil to make its armature slower to act than the other armature and also slower to pick up than to release its armature.

9. In a light signal of the Searchlight type, a movable spectacle biased to one position and movable to a second and a third position for selecting the indications to be displayed by the signal, two electromagnetic operators, each including an armature and an energizing coil for moving its armature from a retracted to an attracted position, means operatively connecting the armatures to the movable spectacle so that the movable spectacle assumes its second position when the armature associated with one coil is in an attracted position and its third position only when both armatures are in attracted positions, an

energizing circuit for the two coils, contact means in said circuit making the other coil ineffective to move its armature to an attracted position by means of pole changing one part of said other coil with respect to the rest of said other coil until after said one coil has moved its armature to an attracted position, and means associated with said one coil to make its armature slower to act than the other armature and also slower to pick up than to release its armature.

10. In a light signal of the searchlight type, a movable spectacle biased to one position and movable to second and third positions to thereby determine the different indications to be displayed by the signal, two electromagnets each having an armature and a winding for moving its armature from a biased position to an attracted position when such winding is energized, means operatively connecting the arinatures to said movable spectacle for causing the movable spectacle to assume its second position when one of said armatures is in an attracted position and causing said movable member to assume its third position when both of said armatures are in attracted positions, an energizing circuit means including the windings of both electromagnets connected in series, and means including contacts operated by said one armature for rendering the winding of the other electromagnet ineffective to move its armature to an attracted position in response to current flow through said energizing circuit means until said one armature has assumed its attracted position.

THOMAS J. JUDGE.

EEFERENCES CITED The following references are of record in the tile of this patent:

UNITED STATES PATENTS Number Name Date 2,035,395 Merkel Mar. 24, 1936 2,191,186 Moore Dec. 7, 1937 2,172,724 Wells et al Sept. 12, 1939 2,337,651 Douglass Dec. 29, 1943 1,835,150 Field Dec. 8, 1931 1,864,224 Wells June 21, 1932 2,125,257 Field July 26, 1938 

